L.,
Take a deep breath Mama-to-be! I was tired just reading your post. :) I think you have a million things going on right now and you should just break them down and look at them individually.
My mom has a "nursery" for my sons at her house. In fact, when I was pregnant with my first, we planned it that way. And, you know what? It's awesome. I can visit and have a safe place for the boys to play. My older son LOVES his bed at Grandmas and loves to spend the night. And, when we visit for the afternoon - we don't even need to schedule it around nap times. (Which you will see is an issue.) Both boys are comfortable sleeping in "their" room at Grandmas. She also has her den set up with a ton of toys for them so we don't need to bring anything when we come visit. It makes it 1000 times easier.
On the other hand, my in-laws have made it close to impossible to even bring our sons over to visit. Our 9 month old has never been there and our 3 y/o has only been there like 4-5 times. They live about 30 minutes away.
The name thing? People get over it. My husbands Grandma is a strict Catholic and she didn't care for the name we picked out (Jacob). She said it "sounds Jewish". Oh well. She even said, "Well I won't call him Jacob. I'll call him Jack." My pregnant response? "Well he won't listen, because his name will be Jacob." There will NEVER be a name that everyone agrees on. I can see why people don't tell sometimes. Once the baby is here, it's harder to say something bad about the name with the beautiful little one looking right at you. Lol. We named our sons what WE wanted to and to heck with everyone else. Our second son has a unique middle name and we get questioned about it all the time. He carries the maiden name of my Grandma that passed away the year he was born (O'Day). It's interesting to see the reaction when people question it and I give the reason. :)
Finally, the shower. It's so funny how all these things seem so important - and they ARE important, I know. But, in the long run as long as you have enough (good) food, friends and family - no one will remember what "theme" you had. I can appreciate your sister wanting to give you a perfect shower and I think it's awesome that she's willing to do it from so far away. I had nothing to do with my shower, and I prefered it that way. My Mom, Sister and MIL arranged it and did everything. I just needed to show up. It was great. I don't remember what the plates looked like, the colors of the table cloth or anything. I DO remember all of my friends and family there to celebrate the upcoming arrival of our son.
So, just sit back and let your sister and Mom work out the details. Provide a list of the people you want to be invited and relax and look forward to the day.
There are so many things that you will stress about in the next few months. Your Mom is just very excited about her grandson. And, I can tell you from experience that yea, sometimes it's over the top with my mom and her adoration of our boys...BUT, to see my 3 year old scream with uncontrolled excitement when he sees her is just awesome. And, the memories I have with my late-Grandma are cherished.
Congrats on your pregnancy.
I wish you the best!
T.